1. CRC for Forestry, University of Tasmania, Private Bag 12, Hobart, TAS, 7001, Australia.
2. Department of Forest Resources Management, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
3. Faculty of Forestry, University of Toronto, Toronto, ON M5S 3B3, Canada.
4. Department of Industrial Engineering, University of Chile, P.O. Box 2777, Santiago, Chile.